JP2010058991A - Method and apparatus for manufacturing hydrogen and fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing hydrogen where hydrogen generation is simply and efficiently stopped and to obtain a fuel cell system having the apparatus for manufacturing hydrogen. <P>SOLUTION: In the method for manufacturing hydrogen where hydrogen is manufactured by supplying water to a hydrogen generating material containing a hydrogen generating substance generating hydrogen by an exothermic reaction with water, the reaction rate of the hydrogen generating material which is a ratio of used amount for hydrogen generation in the hydrogen generating material is detected when stopping hydrogen manufacturing, and when the reaction rate of the hydrogen generating material is larger than a threshold at the stopping, excess hydrogen is generated by continuing hydrogen manufacturing and then excess hydrogen is utilized separately. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydrogen production method for generating hydrogen by reacting a hydrogen generating material and water, a hydrogen production apparatus for producing hydrogen by the production method, and a fuel cell system including the hydrogen production apparatus.

  In recent years, with the spread of cordless devices such as personal computers and mobile phones, batteries as the power source are increasingly required to be smaller and have higher capacity. Currently, lithium ion secondary batteries have been put into practical use as secondary batteries that have high energy density and can be reduced in size and weight, and demand for portable power sources is increasing. However, this lithium ion secondary battery has a limit in output capacity, and there is a problem that sufficient continuous use time cannot be guaranteed depending on the type of cordless device used.

  In order to solve such problems, development of fuel cells such as solid polymer fuel cells has been underway. The fuel cell can be used continuously if fuel and oxygen are supplied. For example, a polymer electrolyte membrane fuel cell (PEMFC) uses a solid polymer electrolyte as the electrolyte, oxygen in the air as the positive electrode active material, and fuel (hydrogen, methanol, etc.) as the negative electrode active material Therefore, it is attracting attention as a battery that can be expected to have a higher energy density than a lithium ion secondary battery.

  As a method of supplying hydrogen, which is a fuel, to such a fuel cell, a method of generating hydrogen by reacting water with a hydrogen generating substance such as aluminum, magnesium, silicon, or zinc has been proposed.

  By the way, when an actual use scene of a cordless device or the like is assumed, not only when the user uses the device continuously, but also when the device is used intermittently with repeated operation and stoppage. Therefore, even when hydrogen is used as a fuel for the fuel cell, hydrogen generation is stopped at an arbitrary timing, and again at a predetermined timing, and then hydrogen generation is started again. There is a need for a method of intermittently generating hydrogen so as to maintain the generated state.

  In the method of producing hydrogen by the reaction of water and the hydrogen generating material as described above, hydrogen generation is immediately performed even if the supply of water to the hydrogen generating material is stopped while the hydrogen generating reaction is stably maintained. The reaction does not stop. For this reason, in the method of producing hydrogen, which is fuel for fuel cells, by the reaction of water and hydrogen generating materials, hydrogen generation occurs when power generation in the fuel cell is no longer necessary because the user has stopped using the equipment. It is a problem to perform the stop well.

As a method for solving such a problem, a solid hydrogen generating material is divided and accommodated in a plurality of accommodating spaces, and this is reacted with water in turn, so that when hydrogen supply is stopped, There has been proposed a method of stopping the occurrence of the above (see Patent Document 1).
JP 2007-63029 A

  The conventional hydrogen production method uses a fact that the volume of a hydrogen generating material expands when it reacts with water, and sequentially reacts a plurality of hydrogen generating materials with water without using a switching means. Is.

  However, in order to control the amount of hydrogen generation more accurately by the conventional method, it is necessary to divide and store the hydrogen generating material into as many sections as possible. If it does in this way, the volume ratio of the partition with respect to the internal volume of the container which accommodates hydrogen generating material will increase, and the energy efficiency which can be generated with respect to the volume of a hydrogen generator will fall. Therefore, it is not preferable as a fuel source of a fuel cell for which a smaller power source is required as a power source of a portable device.

  The present invention has been made in view of such circumstances, and an object thereof is to obtain a hydrogen production method and a hydrogen production apparatus capable of easily and efficiently stopping the generation of hydrogen, and a fuel cell system having the hydrogen production apparatus. And

  In order to solve the above problems, the hydrogen production method of the present invention is a hydrogen production method for producing hydrogen by supplying water to a hydrogen generation material containing a hydrogen generation material that generates hydrogen by an exothermic reaction with water. When the production of hydrogen is stopped, a reaction rate that is a ratio of the amount already used for hydrogen generation in the hydrogen generating material is detected, and the reaction rate of the hydrogen generating material is larger than a stop threshold value. Is characterized in that the production of hydrogen is continued to generate surplus hydrogen, and the surplus hydrogen is used separately.

  Further, the hydrogen production apparatus of the present invention includes a container capable of storing a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water, a predetermined supply time for the hydrogen generating material in the container, A water supply means capable of supplying water at a predetermined supply rate; and a reaction rate detection means for detecting a reaction rate which is a ratio of an amount already used for hydrogen generation in the hydrogen generating material. It is used for the hydrogen production method according to the invention.

  Furthermore, a fuel cell system according to the present invention includes the hydrogen production apparatus according to the present invention and a fuel cell that generates power using the hydrogen produced by the hydrogen production apparatus.

  According to the hydrogen production method of the present invention, in the hydrogen production method for producing hydrogen by supplying water to the hydrogen generation material, the reaction rate of the hydrogen generation material is confirmed when the production of hydrogen is stopped, and the reaction rate is high. In some cases, surplus hydrogen is generated and utilized without stopping the production of hydrogen. For this reason, hydrogen generated after hydrogen production is no longer necessary can be used effectively, and because the reaction rate is high, it is difficult to resume hydrogen production if hydrogen production is stopped. Can be used to efficiently produce hydrogen.

  Moreover, the hydrogen generator of this invention is a hydrogen production apparatus suitable for implementing the hydrogen production method of this invention.

  Furthermore, the fuel cell system of the present invention can provide a fuel cell system suitable for use as a power source for a cordless device or the like by including the hydrogen production apparatus of the present invention.

  As described above, in the hydrogen production method according to the present invention, in the hydrogen production method for producing hydrogen by supplying water to a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water, When the production is stopped, a reaction rate, which is a ratio of the amount already used for hydrogen generation in the hydrogen generating material, is detected, and when the reaction rate of the hydrogen generating material is larger than a stop threshold value, The production of hydrogen is continued to generate surplus hydrogen, and the surplus hydrogen is used separately.

  By doing in this way, since the reaction rate of the hydrogen generating material is higher than a predetermined level, hydrogen is continuously generated from the hydrogen generating material that is difficult to restart once hydrogen production is stopped. Surplus hydrogen can be used effectively. For this reason, surplus hydrogen produced | generated after the necessity for hydrogen production is lost can be used effectively, and the amount of hydrogen obtained from a hydrogen generating material can be improved.

  In the present invention having the above configuration, it is preferable to store and use the surplus hydrogen, or to generate power with a fuel cell using the surplus hydrogen, and to use the generated power by charging the secondary battery. . By doing in this way, surplus hydrogen can be used effectively.

  In addition, when hydrogen production is started again after the hydrogen production is stopped, if the reaction rate of the hydrogen generating material is larger than the restart threshold, the hydrogen production is not started and the hydrogen generating material It is preferable to perform a warning display informing the replacement. By doing so, it is possible to inform the user that the reaction rate is equal to or higher than a predetermined level and it is difficult to restart hydrogen generation, and to promote replacement of the hydrogen generating material.

  Detecting a reaction rate of the hydrogen generating material from a total amount of produced hydrogen; and a reaction rate of the hydrogen generating material, a container in which the hydrogen generating material is accommodated, and a container accommodating portion in which the container is accommodated. It can be detected by the pressure between.

  Further, the hydrogen generating material contained in the hydrogen generating material is preferably at least one metal material selected from the group consisting of aluminum, silicon, zinc, magnesium and alloys mainly composed of these elements. .

  Furthermore, it is preferable that the hydrogen generating material further includes a heat generating material that generates heat by reacting with water in addition to the hydrogen generating material. In this case, the heat generating material is an oxide of an alkaline earth metal. It is preferable. Moreover, it is preferable that the content rate of the said hydrogen generating substance in the said hydrogen generating material is 85 to 99 weight%.

  The hydrogen production apparatus according to the present invention includes a container capable of storing a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water, and a predetermined supply time for the hydrogen generating material in the container. Water supply means capable of supplying water at a predetermined supply rate; and a reaction rate detection means for detecting a reaction rate which is a ratio of the amount already used for hydrogen generation in the hydrogen generating material, Used in the method for producing hydrogen according to the present invention.

  In this way, the reaction rate of the hydrogen generating material is detected, and when it is determined that the reaction rate is equal to or higher than a predetermined threshold, surplus hydrogen is generated without stopping hydrogen production. Thus, a hydrogen production apparatus suitable for carrying out the hydrogen production method of the present invention can be obtained.

  In this configuration, it is preferable that the container is detachable and further has a stopper for restricting the detachment of the container.

  Furthermore, the fuel cell system of the present invention includes the above-described hydrogen production apparatus of the present invention and a fuel cell that generates electric power using the hydrogen produced by the hydrogen production apparatus.

  In this way, by taking advantage of the characteristics of the hydrogen production method according to the present invention, it is possible to simply and efficiently stop the generation of hydrogen even when the generation and stop of hydrogen as fuel for the fuel cell are repeated. Can do. For this reason, a fuel cell system suitable for use as a power source for a cordless device or the like can be provided.

  Moreover, it is preferable to further provide a secondary battery in which electric power generated by the fuel cell using the surplus hydrogen is charged. By doing in this way, surplus hydrogen can be effectively utilized as a fuel cell system.

  Hereinafter, embodiments of a hydrogen production method, a hydrogen production apparatus, and a fuel cell system according to the present invention will be described with reference to the drawings.

(Embodiment 1)
First, the hydrogen production method of the present invention will be described as Embodiment 1 of the present invention.

  The hydrogen production method of the present invention is to produce hydrogen by supplying water to a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water. Then, when hydrogen production is stopped from the state where hydrogen is being produced, the reaction rate, which is the ratio of the amount already used in the production of hydrogen by reacting with water in the hydrogen generating material, is detected and reacted. If the rate is greater than the stop threshold, surplus hydrogen is produced without stopping the hydrogen production. The surplus hydrogen is stored as it is or power is generated by a fuel cell using the surplus hydrogen, and the power is charged in a secondary battery and used separately.

  The hydrogen production method of the present embodiment has a high reaction rate of the hydrogen generating material when hydrogen production is stopped in a state where hydrogen production is being performed, which is obtained as a result of extensive studies by the present inventors. And based on the knowledge that it is extremely difficult to resume hydrogen generation after stopping. Such a hydrogen production method is particularly effective when producing hydrogen as a fuel for a fuel cell used as a power source for a cordless device or the like.

  When hydrogen production is performed as a power source fuel for a cordless device, intermittent hydrogen production may be required depending on the use state of the user. If the reaction rate of the hydrogen generating material is low, the reaction rate of the hydrogen generating material is high and the amount of unreacted hydrogen generating material is reduced. If hydrogen production is stopped, it will be difficult to start hydrogen production again. Such a state is a problem in terms of effective utilization of the hydrogen generating material because hydrogen that can be generated cannot be obtained when hydrogen production is continuously performed. In addition, the fact that hydrogen production cannot be resumed and power generation from the fuel cell stops because there is no fuel means that, from the user's point of view, the equipment that had been used up until now can no longer be used. However, the hydrogen production method of the present invention can effectively solve these problems.

  The “reaction rate” referred to in this specification is the amount of hydrogen already generated at the time of detection relative to the theoretical amount of hydrogen generated when it is assumed that all the hydrogen generating material has reacted with water. Therefore, a hydrogen generating material having a reaction rate of 0% means a hydrogen generating material in a state where no reaction with water has yet occurred. The theoretical hydrogen generation amount when the hydrogen generating material is aluminum is about 1360 ml in terms of 25 ° C. per 1 g of aluminum.

  In describing the hydrogen production method of the present embodiment, first, hydrogen generation by an exothermic reaction between a hydrogen generating material contained in the hydrogen generating material and water in the present embodiment will be described.

  The hydrogen generating substance used in the hydrogen production method of the present embodiment is not particularly limited as long as it is a material that reacts as water to generate hydrogen, but aluminum, silicon, zinc, magnesium, and alloys mainly composed of these elements At least one metal material selected from the group consisting of can be preferably used. In the case of an alloy, metal components other than the main element are not particularly limited. In addition, the main body refers to a substance that is contained in an amount of 80% by weight or more, more preferably 90% by weight or more based on the entire alloy. The metal material described above is a substance that hardly reacts with water at room temperature, but can easily exothermic reaction with water when heated. Here, “normal temperature” is a temperature in the range of 20 to 30 ° C.

  Such a metal material can generate hydrogen by reacting with water at least in a state of being heated to room temperature or higher. However, since a stable oxide film is formed on the surface, it is a substance that does not generate hydrogen or hardly generates hydrogen at a low temperature or in a bulk shape such as a plate shape or a block shape. However, handling in air is easy due to the presence of the oxide film.

  For example, it is considered that the reaction between aluminum, which is one of the metal materials, and water proceeds according to any of the following formulas (1) to (3). The calorific value according to the following formula (1) is 419 kJ / mol.

2Al + 6H2O → Al2O3 · 3H2O + 3H2 (1)
2Al + 4H2O → Al2O3 · H2O + 3H2 (2)
2Al + 3H2O → Al2O3 + 3H2 (3)
Moreover, although the said metal material is not specifically limited by the average particle diameter, It is preferable that the average particle diameter shall be 0.1 micrometer or more and 100 micrometers or less, and 0.1 micrometer or more and 50 micrometers or less are more preferable. As described above, the metal material generally has a stable oxide film formed on the surface. Therefore, a metal material such as a plate shape, a block shape, and a bulk shape having a particle diameter of 1 mm or more does not cause a reaction with water even when heated, and may not substantially generate hydrogen. However, when the average particle size of the metal material is 100 μm or less, the action of suppressing the reaction with water by the oxide film is reduced, and although it is difficult to react with water at room temperature, the reactivity with water increases when heated, and the hydrogen generation reaction Will continue. When the average particle size of the metal material is 50 μm or less, hydrogen can be generated by reacting with water even under mild conditions of about 40 ° C.

  Even when the average particle size of the metal material exceeds 50 μm, if the metal material is scaly and the thickness is 5 μm or less, the reactivity with water is increased, and hydrogen is more efficiently produced. In particular, when the thickness of the metal material is 3 μm or less, the reaction efficiency can be further improved.

  On the other hand, if the average particle size of the metal material is less than 0.1 μm, or the thickness of the scale-like metal material is less than 0.1 μm, the ignitability becomes high and handling becomes difficult, or the packing density of the metal material is The energy density is likely to decrease due to a decrease. For these reasons, the average particle diameter of the metal material is preferably 0.1 μm or more, and when the metal material is scale-like, the thickness is preferably 0.1 μm or more. .

  In addition, said average particle diameter means D50 which is the value of the particle diameter in the volume-based integrated fraction of 50%. As a method for measuring the average particle diameter, for example, a laser diffraction / scattering method or the like can be used. More specifically, it is a particle diameter distribution measurement method using a scattering intensity distribution detected by irradiating a measurement target substance dispersed in a liquid phase such as water with laser light. As a particle size distribution measuring apparatus using a laser diffraction / scattering method, for example, “Microtrac HRA (product name)” manufactured by Nikkiso Co., Ltd. can be used.

  The thickness of the scale-like metal material can be observed with a scanning electron microscope (SEM).

  Further, the shape of the metal material is not particularly limited, and examples thereof include a substantially spherical shape (including a true spherical shape), a rugby ball shape, and a scale-like shape as described above. In the case of a substantially spherical shape or a rugby ball shape, those satisfying the above average particle diameter are preferable, and in the case of a scale shape, those satisfying the above thickness are preferable. In the case of a scale-like metal material, it is more preferable that the above average particle diameter is also satisfied.

  If at least one substance selected from the group consisting of a hydrophilic oxide, carbon, and a water-absorbing polymer (hereinafter referred to as an additive) is added to the metal material that is a hydrogen generating substance, the metal material and This is preferable because the reaction with water can be promoted. As such a hydrophilic oxide, alumina, silica, titania, magnesia, zirconia, zeolite, zinc oxide and the like can be used.

  Furthermore, in the hydrogen production method of this embodiment, in order to easily start an exothermic reaction between water and the hydrogen generating substance, the hydrogen generating material used is a material other than the hydrogen generating substance such as the metal material. It is preferable to include a heat generating material that generates heat by reacting with water.

  As a heat generating material, a material that reacts with water to become a hydroxide or a hydrate, a material that generates heat with water and generates hydrogen, and the like can be used. Among such heat generating materials, materials that react with water to form hydroxides or hydrates include, for example, alkali metal oxides (for example, lithium oxide), alkaline earth metal oxides ( For example, calcium oxide, magnesium oxide, etc.), alkaline earth metal chlorides (eg, calcium chloride, magnesium chloride, etc.), alkaline earth metal sulfate compounds (eg, calcium sulfate, etc.), and the like are used. it can. Examples of the substance that reacts with water to generate hydrogen include alkali metals (eg, lithium, sodium, etc.), alkali metal hydrides (eg, sodium borohydride, potassium borohydride, lithium hydride, etc.). ) Etc. can be used. These substances may be used alone or in combination of two or more.

  In addition, if the heat generating material is a basic material, it dissolves in water used for the hydrogen generation reaction to form a highly concentrated alkaline aqueous solution. Therefore, an oxide film formed on the surface of the metal material that is a hydrogen generating material is formed. It is preferable because it can be dissolved to increase the reactivity with water. The reaction for dissolving the oxide film may be the starting point for the reaction between the metal material and water. In particular, if the heat generating material is an alkaline earth metal oxide, it is more preferable because it is a basic material and easy to handle.

  As exothermic materials, substances that generate an exothermic reaction with substances other than water at room temperature, for example, substances that react with oxygen and generate heat, such as iron powder, are also known. However, when the hydrogen generating material includes a substance that reacts with the oxygen and a metal material that is the hydrogen generating substance, oxygen required for the reaction simultaneously reduces the purity of the hydrogen generated from the metal material. Such as reducing the amount of hydrogen generated by oxidizing the metal material. For this reason, as described above, it is preferable to use an alkaline earth metal oxide or the like that generates heat by reacting with water as the heat generating material in the present embodiment. For the same reason, the exothermic material contained in the hydrogen generating material is preferably one that does not generate a gas other than hydrogen during the reaction.

  From the viewpoint of generating more hydrogen, the content of the hydrogen generating material such as the above-described metal material in the entire hydrogen generating material is preferably 85% by weight or more, more preferably 90% by weight or more. From the viewpoint of further ensuring the effect of the combined use of materials, it is preferably 99% by weight or less, more preferably 97% by weight or less. Further, the content of the heat generating material in the entire hydrogen generating material is preferably 1% by weight or more, more preferably 3% by weight or more, preferably 15% by weight or less, more preferably 10% by weight or less.

  A hydrogen generating material containing a heat generating material can be obtained by mixing a metal material or the like which is a hydrogen generating material with a heat generating material. When mixing the metal material and the heat generating material, it is preferable that only the metal material does not form an aggregate of 1 mm or more. For example, by stirring and mixing the metal material and the heat generating material, the hydrogen generating material can be produced while suppressing the aggregation of the metal material. Alternatively, the surface of the metal material may be combined with a heat generating material to form a hydrogen generating material.

  Next, a method for stopping hydrogen production in the hydrogen production method according to the present embodiment will be described in detail. FIG. 1 is a flowchart showing steps when hydrogen production is stopped in the hydrogen production method of the present embodiment.

  As shown in FIG. 1, in the first step S101, an instruction to stop hydrogen generation is given.

  In the subsequent step S102, the reaction rate X of the hydrogen generating material at the time when the hydrogen production stop is instructed is detected. The reaction rate of the hydrogen generating material is determined by, for example, a flow meter installed in a path for generating and supplying hydrogen with respect to the amount of hydrogen that can be theoretically generated, obtained from the amount of the hydrogen generating material used. It can be determined as a ratio to the total amount of hydrogen actually generated.

  Further, as another method for obtaining the reaction rate, a method of measuring the volume expansion of the container containing the hydrogen generating material by a pressure sensor installed between the container containing the container and surrounding the container is conceivable. . The reaction product produced when the hydrogen generating material reacts with water to generate hydrogen usually has a larger volume than the hydrogen generating material. Therefore, as the reaction between the hydrogen generating material and water proceeds, the total volume of water, the unreacted hydrogen generating material, and the reaction product generated by reacting with water monotonously increases. To do. When the container containing the hydrogen generating material is made of, for example, a resin such as polyethylene, volume expansion occurs as the hydrogen generating reaction between the hydrogen generating substance and water proceeds. By grasping the volume expansion ratio by using the pressure applied between the container and the container housing portion arranged so as to surround the container, the reaction rate of the hydrogen generating substance can be grasped.

  Here, as long as the container accommodating part can accommodate a container in which a hydrogen generating material is accommodated and can accurately measure the pressure applied between the container and the container accommodating part, The shape is not particularly limited. However, considering the temperature of the container to be about 100 ° C. and the magnitude of pressure received due to the volume expansion of the container accompanying the reaction between the hydrogen generating material and water, It is preferable to select a material that does not deform or break. From such a viewpoint, a metal such as aluminum or iron can be used as the material of the container housing portion.

  In subsequent step S103, it is determined whether or not the reaction rate X of the hydrogen generating material is equal to or greater than the stop threshold value x1.

  Here, when the reaction rate of the hydrogen generating material exceeds this value, the threshold value x1 at the time of stopping is that the reaction between the hydrogen generating material and water has progressed to a certain extent, and the hydrogen production is once stopped. In this case, it is a reference value that it is difficult to restart a stable hydrogen generation reaction.

  As the reaction between the hydrogen generating material and water proceeds, the proportion of the hydrogen generating material that has not yet reacted with water decreases, making it difficult to immediately react with the supplied water. Although the reaction between the hydrogen generating material and water is an exothermic reaction, the hydrogen generating material that has already reacted with water to become a reaction product does not rise in temperature even when water is supplied. When the ratio of the reacted hydrogen generating material in the accommodated container increases, it becomes difficult to sufficiently raise again the temperature of the hydrogen generating material in the container once the hydrogen production is stopped and lowered. Due to these reasons, the stop threshold value x1 appears in the reaction rate of the hydrogen generating material.

  This stop threshold x1 varies depending on conditions such as the type of hydrogen generating material in the hydrogen generating material, the proportion of the hydrogen generating material in the hydrogen generating material, and the total amount of the hydrogen generating material, but may be set to 60%, for example. it can.

  If it is determined in step S103 that the reaction rate X of the hydrogen generating material is not equal to or greater than the stop threshold value x1 (in the case of No), the reaction of the hydrogen generating material with water has not progressed so much, and once hydrogen is produced. In this case, it is considered that hydrogen production can be resumed by supplying a predetermined amount of water again. Therefore, in this case, the process proceeds to the next step S104.

  In step S104, the supply of water to the hydrogen generating material is immediately stopped in response to the hydrogen generation stop request, and the hydrogen generation reaction is terminated. Then, a series of hydrogen production stop operations ends.

  On the other hand, if it is determined in step S103 that the reaction rate X of the hydrogen generating material is equal to or greater than the stop threshold value x1 (in the case of Yes), the reaction of the hydrogen generating material with water has progressed and hydrogen production is once performed. If it stops, it is a case where it is considered difficult to restart hydrogen production. In this case, if the supply of water to the hydrogen generating material is immediately stopped in response to a hydrogen generation stop request and the hydrogen generating reaction is terminated, the remaining water and the unreacted hydrogen generating material are effectively used. There is a high risk of not being able to use it. Therefore, in this case, the process proceeds to step S105.

  In step S105, surplus hydrogen is produced by supplying water to the hydrogen generating material at the water supply speed v1. This water supply rate v1 is preferably the same as the rate at which water was supplied during hydrogen production in a steady state, which was performed before the hydrogen production in the flowchart shown in FIG. 1 was stopped. In this step S105, since the supply of water has not been stopped yet, the normal hydrogen production conditions that have been performed so far are continued, and hydrogen production is continued efficiently and stably. Because it can.

  The temperature at which hydrogen can be continuously generated is usually 40 ° C. or higher. When the exothermic reaction between the hydrogen generating material and water starts and the generation of hydrogen begins, the internal pressure of the container rises and the water In some cases, the boiling point of the container may increase, and the temperature in the container may reach about 120 ° C. From the viewpoint of controlling the hydrogen generation rate, the temperature is preferably 100 ° C. or lower.

  The surplus hydrogen produced in the surplus hydrogen generation process started in step S105 is stored in a hydrogen storage container or the like via a path different from the original hydrogen supply path. This is because the hydrogen production stop step described as the present embodiment does not require hydrogen supply to the regular hydrogen supply path. If the hydrogen generator produces hydrogen as fuel for the fuel cell, the surplus hydrogen is supplied to the fuel cell as it is to generate power, and the power generated by the secondary battery connected to the fuel cell is generated. Can also be stored. In any case, by securing the surplus hydrogen produced at a stage where there is no demand for its original use in a form that can be separately utilized later, hydrogen production is temporarily stopped according to the hydrogen generation stop request. In such a case, it is possible to secure hydrogen that is highly likely not to be obtained when hydrogen production is resumed and to use it effectively.

  In step S105, after surplus hydrogen is produced for a predetermined time, after a predetermined time has passed, the process proceeds to step S106 and the water supply is stopped. Note that how long the surplus hydrogen production started in step S105 is performed takes into account, for example, the capacity of a hydrogen tank that stores surplus hydrogen and the capacity of a secondary battery that can store the power of the fuel cell. However, it is preferable to set appropriately from the viewpoint of securing the maximum hydrogen that can be separately utilized.

  A preferred example in the case of charging a secondary battery connected to a fuel-producing cell will be described later as a third embodiment.

  As described above, in the hydrogen production method of the present embodiment, when a hydrogen production stop request is issued, the hydrogen production is not stopped immediately, but the reaction rate of the hydrogen generating material is detected, and the reaction rate is a predetermined stop. If it is greater than the hour threshold, the hydrogen production is stopped after the surplus hydrogen is produced. By doing so, when the hydrogen generation material has a high reaction rate, once hydrogen production is stopped, it is difficult to resume hydrogen production, and the hydrogen production capacity of the hydrogen generation material is lost. This can be effectively prevented.

  In addition, by securing surplus hydrogen in the form as it is or in the form of power generated by the fuel cell, this surplus hydrogen and the obtained power can be used when instructions for hydrogen production are given again later. Thus, it becomes possible to promptly respond to a request for resumption of hydrogen production.

  Next, a method for restarting hydrogen production in the hydrogen production method of the present embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing steps in the case of resuming hydrogen production in the hydrogen production method of the present embodiment.

  As shown in FIG. 2, in the first step S201, it is requested that the production of hydrogen be started.

  Subsequently, in step S202, the reaction rate X of the hydrogen generating material is acquired. As described above, the reaction rate X of the hydrogen generating material is grasped by a flow meter installed in the hydrogen generating section with respect to the amount of hydrogen that can be theoretically generated from the amount of the hydrogen generating material used. It can be determined as a ratio to the total amount of hydrogen actually generated. Further, the volume expansion of the container containing the hydrogen generating material can be measured by a pressure sensor installed between the container container disposed so as to further surround the container.

  In the next step S203, it is determined whether or not the reaction rate X of the hydrogen generating material is equal to or greater than a predetermined restart threshold value x2. This restart threshold value x2 is that most of the hydrogen generating material has already reacted with water to become a reaction product, and even if water is newly supplied, a practically sufficient amount of hydrogen is continuously generated. The reaction rate is not possible.

  The value of the restart threshold value x2 may be a little higher than the stop threshold value x1 or may be the same value. The restart threshold value x2 is set to a value slightly higher than the stop threshold value x1 even if the supply of water is stopped immediately after a stop request is issued when hydrogen production is stopped. This is because the reaction proceeds and the reaction rate increases. The restart threshold value x2 is also set as appropriate depending on conditions such as the type of hydrogen generating material in the hydrogen generating material, the ratio of the hydrogen generating material to the hydrogen generating material, the total amount of the hydrogen generating material, and the like. The numerical value is determined, and can be 65%, for example.

  When the reaction rate X of the hydrogen generating material is not equal to or greater than the restart threshold value x2 (in the case of No), it is determined that hydrogen can be continuously produced from the hydrogen generating material, and the process proceeds to step S204, The supply of water is started at the supply speed v2 and hydrogen production is resumed.

  Note that the predetermined supply rate v2 at the time of restarting the hydrogen generation may basically be a supply rate at which hydrogen production can be stably continued. The case where hydrogen production is resumed in step S204 is a case where the reaction rate of the hydrogen generating material is smaller than the restart threshold value x2 in step S203. This is because it is considered that hydrogen production can be started stably by supplying. Instead of supplying water at a steady rate from the beginning when hydrogen production is resumed, water is initially fed at a faster rate than the steady water supply rate, depending on the temperature of the hydrogen generating material and the detected reaction rate. Needless to say, it is possible to take appropriate measures such as supplying water to cause a hydrogen generation reaction between water and a hydrogen generating substance quickly.

  The specific value of the water supply rate v2 is, for example, preferably 5 μl / min or more, more preferably 10 μl / min or more, and more preferably 20 μl / min or more per 1 g of hydrogen generating material in the hydrogen generating material. It is particularly preferable to do this. For example, it is preferably 200 μl / min or less, more preferably 100 μl / min or less, and particularly preferably 50 μl / min or less.

  In addition, as water supply speed v1 in the case of manufacturing surplus hydrogen in step S105 in FIG. 1, since it can be set as a steady water supply speed as above-mentioned, it is set as the above-mentioned water supply speed v2. be able to. However, when surplus hydrogen is produced, the water supply rate v1 may be set slightly higher than the water supply rate v2 in consideration of the high reaction rate of the hydrogen generating material. it can.

  On the other hand, when the reaction rate X of the hydrogen generating material is equal to or greater than the restart threshold value x2 (in the case of Yes), it is determined that it is difficult to continuously produce hydrogen from the hydrogen generating material, and the process proceeds to step S205. .

  In step S205, Alert is turned on to inform the user that hydrogen cannot be produced from the hydrogen generating material. Then, the user removes the container containing the hydrogen generating material having a high reaction rate and replaces it with a container containing the hydrogen generating material having a reaction rate of 0% or at least lower than the restart threshold x2. It is preferable to prompt.

  The display method of Alert that the hydrogen generating material cannot stably produce hydrogen is not particularly limited, but it is preferably displayed by a known display unit such as a liquid crystal display, a dial, an LED lamp. The display content may be a specific display of the reaction rate X, and it is displayed that the container should be replaced as a result of determining whether the reaction rate X is equal to or greater than the restart threshold x2. May be. However, the Alert display in step S205 is not essential in the hydrogen production method of the present embodiment.

  In the hydrogen production method of this embodiment, since the reaction rate of the hydrogen generating material is detected, it may be possible to constantly display the detected reaction rate of the hydrogen generating material on the display unit. The reaction rate of the hydrogen generating material can be grasped as the remaining amount of the fuel cell when, for example, the produced hydrogen is used as the fuel of the fuel cell. Therefore, it is possible to inform the user how much hydrogen production capacity is available before hydrogen production becomes impossible, so that the user can use the hydrogen generator safely and contain the hydrogen generating material. The user can be promptly prepared to replace the used container, which improves usability.

(Embodiment 2)
Next, a fuel cell system including the hydrogen production apparatus of the present invention, and the hydrogen production apparatus and a fuel cell using hydrogen produced by the hydrogen production apparatus as fuel will be described as Embodiment 2 of the present invention. . The hydrogen production apparatus of the present invention is used in the hydrogen production method of the present invention described as the first embodiment. For this reason, in the following description, in the description part regarding the hydrogen production method, the description overlapping with the content already described in Embodiment 1 may be omitted as appropriate.

  FIG. 3 is a schematic configuration diagram illustrating an example of a hydrogen production apparatus and a fuel cell system according to the present embodiment.

  The hydrogen production apparatus 100 according to the present embodiment includes a container 1 that can store a hydrogen generating material 2 containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water, and a hydrogen generating material 2 stored in the container 1. A water storage container 3 for storing water 4 that generates hydrogen by an exothermic reaction, a pump 10 as water supply means for supplying water 4 from the water storage container 3 to the container 1, and a hydrogen generating material stored in the container 1 Pressure sensor 11 as a reaction rate detecting means for detecting a reaction rate of 2, a container housing part 9 for housing the container 1, a heat insulating material 17 covering the container housing part 9, and a reaction rate of the hydrogen generating material 2 from the output of the pressure sensor 11 The control part 12 which adjusts the supply amount of the water 4 is detected and discriminated and the pump 10 is controlled. In FIG. 3, the container 1 and the water storage container 3 are cross-sectional views in order to show the internal structure.

  The container 1 has a lid 1a and a container body 1b. A water supply pipe 5 for supplying water 4 stored in the water storage container 3 through the lid 1a and a hydrogen outlet pipe 8 for leading the generated hydrogen are provided in the container main body 1b. ing. The water 4 sent from the water storage container 3 by the pump 10 is supplied to the hydrogen generating material 2 in the container 1 from the water supply port 6 of the water supply pipe 5 and is generated by the reaction of the hydrogen generating material 2 and the water 4. The hydrogen thus introduced is guided from the hydrogen outlet 7 through the hydrogen outlet 8 to the hydrogen supply channel 14.

  Further, the hydrogen generating material 2 can contain a heat generating material. When the hydrogen generating material 2 containing such a heat generating material is accommodated in the container main body 1b and water 4 is supplied to react with it, the heat generating material is dispersed or mixed with the hydrogen generating material uniformly or non-uniformly. Can be used as a mixture. However, in the container main body 1b, it is more preferable to provide an unevenly distributed portion having a heat generation material content higher than the average content of the heat generation material in the entire hydrogen generating material 2, and water in the water supply pipe 5 inside the container main body 1b. It is particularly preferable to arrange the uneven distribution portion in the vicinity of the supply port 6. By unevenly distributing the heat generating material in the inside of the container main body 1b, it is possible to shorten the time from the start of supplying the water 4 until the hydrogen generating substance is heated, and to generate hydrogen more quickly. can do.

  As described above, in order to arrange the unevenly distributed portion in the vicinity of the water supply port 6 inside the container main body 1b, in addition to the method of arranging only the heat generating material in the vicinity of the water supply port 6, the content of the heat generating material is previously determined. Two or more different unit compositions of a hydrogen generating substance and a heat generating material are prepared, and the unit composition having the highest content of the heat generating material is arranged in the vicinity of the water supply port 6, and the other parts are arranged. A unit composition having a low content of exothermic material can also be arranged.

  The water supply pipe 5 and the hydrogen lead-out pipe 8 are provided with an attachment / detachment mechanism 13, and the attachment / detachment mechanism 13 allows the container 1 to be connected to the hydrogen supply flow path 14 and the fuel cell 20 connected thereto, and to contain water. It can be separated from the container 3. When the hydrogen generating material 2 and the water 4 are reacted in the container 1 to generate hydrogen, the hydrogen generating material 2 accommodated in the container 1 is converted into a reaction product and loses the ability to generate hydrogen. For this reason, as the reaction rate, which is the ratio of the hydrogen generating material that has reacted with water to become a reaction product, increases, further hydrogen generation becomes difficult. In such a case described as the case where Alert is displayed in the first embodiment, the container 1 is separated by the attaching / detaching mechanism 13 together with the hydrogen generating material 2 having a high internal reaction rate, and a new hydrogen generating material 2 is accommodated. By exchanging with the container 1, hydrogen can be continuously produced.

  3 shows an example in which the attachment / detachment mechanism 13 is also attached to the water supply pipe 5 so that the container 1 can be separated from the water supply pipe 5. However, the present invention is not limited to this. By reacting with the hydrogen generating material 2, the water 4 stored in the water storage container 3 is also consumed and reduced. For this reason, the container 1 is removed by the attaching / detaching mechanism 13 and replaced with the container 1 containing the new hydrogen generating material. At the same time, the water supply container 3 is also removed and replaced with the water containing container 3 containing the new required amount of water 4. You may do it.

  The container 1 is not particularly limited in its material and shape as long as it can accommodate the hydrogen generating material 2 that generates hydrogen by exothermic reaction with the water 4. However, a material or shape that does not allow water 4 or hydrogen to leak from other than the water supply port 6 and the hydrogen outlet 7 is preferable. As a specific material of the container, a material that hardly permeates water and hydrogen and does not break even when heated to about 100 ° C. is preferable. For example, a metal such as aluminum, iron, and stainless steel, polyethylene (PE), Resins such as polypropylene (PP) can be used. Further, as the shape of the container, a prismatic shape, a cylindrical shape, or the like can be adopted.

  As described above, the reaction product produced by the reaction of the hydrogen generating material 2 with the water 4 is usually larger in volume than the hydrogen generating material 2. Therefore, the container 1 can be deformed in accordance with the reaction between the hydrogen generating material 2 and the water 4 so as not to be damaged when the volume expansion of the built-in material accompanying the generation of such a reactive organism occurs. Is preferred. From such a viewpoint, the material of the container 1 is more preferably a resin such as PE or PP among the materials exemplified above.

  Moreover, it is preferable to install a filter in the hydrogen outlet pipe 8 and the hydrogen outlet 7 provided in the lid 1a of the container 1 so that the water 4 and the hydrogen generating material 2 in the container 1 do not flow out. As this filter, a filter having a property of allowing gas to pass but difficult to pass liquid and solid is preferable. For example, porous polytetrafluoroethylene (PTFE) gas-liquid separation membrane, polypropylene (PP) non-woven fabric, etc. Can be used.

  In the hydrogen production apparatus of the present embodiment shown in FIG. 3, the pump 10 provided in the water supply pipe 5 is controlled by a control signal from the controller 12 at a predetermined supply speed for a predetermined supply time. The water in 3 is supplied into the container 1. For example, a micro pump such as a tube pump, a diaphragm pump, or a syringe pump can be used as the pump 10, but the pump 10 is not limited thereto. As long as the supply rate and time of water to the container 1 can be controlled according to a control signal from the control unit 12, so long as the water supply amount can be adjusted, the specific configuration is not limited.

  The hydrogen produced by the reaction between the hydrogen generating material 2 and the water 4 in the container 1 is led out from the hydrogen lead-out port 7 provided in the container 1 through the hydrogen lead-out pipe 8. The derived hydrogen is sent to a device that uses hydrogen generated by the hydrogen production apparatus of the present embodiment, for example, the fuel cell 20 in the case of FIG. In this embodiment, the hydrogen supply flow path 14 to the fuel cell 20 is provided at the tip of the attachment / detachment mechanism 13 of the hydrogen outlet pipe 8.

  Between the container main body 1b and the container housing part 9, a pressure sensor 11 which is a reaction rate detection means for detecting the reaction rate of the metal material accommodated in the container 1 is attached. In addition, as an attachment position of the pressure sensor 11, if it is a place which can detect the reaction rate of the hydrogen generating material 2 in the container 1, it will not specifically limit. A location where the expansion of the container 1 caused by the volume change is correctly detected as a change in pressure with the container accommodating portion 9 when the hydrogen generating material 2 is changed into a reaction product and its volume is expanded is preferable. For example, as shown in FIG. 3, it is preferable to arrange | position between the container accommodating parts 9 of the side surface of the container main body 1b.

  The outer surface of the container housing portion 9 is covered with a heat insulating material 17. By covering the container housing part 9 with the heat insulating material 17, the heat generated by the exothermic reaction between the hydrogen generating material 2 and the water 4 inside the container 1 is dissipated from the container housing part 9 through the outer wall of the container body 1b. Can be prevented. For this reason, it becomes easy to hold | maintain the temperature which can maintain the exothermic reaction of the hydrogen production | generation started when the water 4 is supplied to the hydrogen generating material 2, and it becomes difficult to receive the influence of external temperature. As a result, hydrogen production can be performed promptly and stably. The material of the heat insulating material 17 is not particularly limited as long as it has a high heat insulating property, and for example, a porous heat insulating material such as polystyrene foam or polyurethane foam, a heat insulating material having a vacuum heat insulating structure, or the like can be used.

  In the hydrogen production apparatus of the present embodiment, the control unit 12 detects the reaction rate of the hydrogen generating material 2 in the container 1 based on the detection signal from the reaction rate detection means such as the pressure sensor 11, and based on the result. Then, the pump 10 is controlled to control the supply of water 4 to the hydrogen generating material 2. By doing in this way, the Alert indication that the control of the amount of water supplied when hydrogen production is stopped, the control of the amount of water supplied when hydrogen production is resumed, and the replacement of the container described in the first embodiment are necessary. Etc.

  In order to have such a function, the control unit 12 preferably uses a programmable control device such as a microcomputer. Further, as shown in FIG. 3, the control unit 12, the pressure sensor 11 serving as the detection means, and the pump 10 for adjusting the supply of water are connected, and detection signals and control signals for the detected information are displayed. Exchange takes place.

  The attachment / detachment mechanism 13 is provided with, for example, a tube formed in a cylindrical shape on the main body side of the apparatus, and the hydrogen outlet tube 8 and the water supply tube 5 connected to the container 1 and the water storage container 3 are inserted therein. Thus, it is possible to employ a configuration in which the insertion portion of the pipe, which is a connection portion, is sealed with a packing such as an O-ring to prevent leakage of hydrogen or water.

  Further, in order to prevent the container 1 from being accidentally dropped off, it is more preferable to provide a stopper 15 on the side of the container 1 opposite to the apparatus main body. And, for example, in a state where the control unit 12 determines that it is not necessary to replace the container 1 according to the detection value of the pressure sensor 11 which is a reaction rate detection means in accordance with a signal from the control unit 12. By preventing the stopper 15 from being removed, it is possible to prevent the container 1 from dropping undesirably or the user from accidentally removing the container 1 that can still be used.

  Although not shown in FIG. 3, it is preferable to provide a display unit for displaying Alert and other warning means described in the first embodiment. As described in the first embodiment, when the reaction rate of the hydrogen generating material 4 is high and it is preferable to replace the container 1, it can be notified to the user with certainty. As a result, usability is improved. This is because not only the improvement but also hydrogen can be efficiently produced again.

  The alert display means or the warning means is not particularly limited, but it is preferable that the alert display means or the warning means be displayed by a known display means such as a liquid crystal display, a dial, or an LED lamp. When the display means is used instead of a simple warning lamp, the reaction rate X may be specifically displayed, and the remaining amount usable as the hydrogen generator is displayed according to the calculation result in the control unit 12. You may do it. The display unit or the warning unit is connected to the control unit 12 and displays the content based on the determination result in the control unit 12.

  Although not shown in FIG. 3, as a hydrogen production apparatus of the present embodiment, a gas-liquid separation unit for separating hydrogen and unreacted water led out from the container 1 into the hydrogen lead-out pipe 8, and And means for returning the water separated by the gas-liquid separator to the water container 3. When the hydrogen generating material 2 and the water 4 react in the container 1, unreacted water may blow out from the hydrogen outlet pipe 8 to the outside of the container 1 as a mixture with hydrogen. In such a case, by providing a gas-liquid separator, the mixture of water and hydrogen discharged from the container 1 is separated into water (liquid) and hydrogen (gas), and the separated water is stored in water. It can be returned to the container 3. By doing in this way, the substantial amount of water supply can be reduced, and the amount of water 4 stored in the water storage container 3 can be reduced. As a result, the volume and weight of the entire hydrogen production apparatus 100 can be reduced and made compact.

  Further, in the hydrogen production apparatus 100 of the present embodiment, in addition to providing the gas-liquid separation unit in the hydrogen outlet pipe 8, a cooling unit (not shown) is provided between the gas-liquid separation unit and the container 1. It is preferable. The inside of the container 1 rises to a temperature near the boiling point of water due to an exothermic reaction between the hydrogen generating material 2 and the water 4. For this reason, it is conceivable that the unreacted water 4 in the container 1 is mixed with the hydrogen into the hydrogen outlet pipe 8 together with hydrogen. Therefore, by providing the cooling section, the water recovery rate in the gas-liquid separation section can be increased by cooling the water vapor flowing into the hydrogen outlet pipe 8 and returning it to liquid water. As the cooling unit, for example, a cooling unit having a structure in which metal cooling fins are arranged so as to be in contact with the hydrogen outlet pipe 8 can be used. Further, an air cooling fan can be used, or a water cooling pipe can be brought close to the hydrogen outlet pipe 8.

  Next, a case where the container 1 is made into a cartridge will be described as an example suitable for further downsizing the hydrogen production apparatus according to the present embodiment.

  FIG. 4 shows a configuration in which the container 1 is a small fuel cartridge so that the hydrogen production apparatus 100 according to the present embodiment is suitable when the produced hydrogen is applied to a small fuel cell or a portable electronic device. It is a typical sectional view shown. In FIG. 4, the cross-sectional hatching is omitted in order to facilitate understanding of each component. Further, parts having the same functions as those of the hydrogen production apparatus shown in FIG. 3 and performing common actions are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 4, a container 1 as a fuel cartridge has a hydrogen generating material 2 enclosed therein, and is generated in the container 1 with a water supply pipe 5 for supplying water to the hydrogen generating material 2. And a hydrogen lead-out pipe 8 for taking out the produced hydrogen to the outside. After the container 1 as a fuel cartridge is mounted on a fuel cell or a portable electronic device, water is supplied into the container 1 through a water supply port 6 of a water supply pipe 5 by a micropump or the like (not shown). As a method of supplying water into the container 1, a water storage container (not shown) filled with water is attached to a part of the container 1 formed as a fuel cartridge in advance, and the fuel cartridge is attached to the fuel cell or portable electronic device. It is also possible to supply the water in the water container into the container 1 after the is mounted.

  As shown in FIG. 4, in the container 1 formed as a fuel cartridge, a water absorbing material 16 is disposed above and below the hydrogen generating material 2, and the water supply port 6 at the tip of the water supply pipe 5 is connected to the hydrogen generating material 2. It arrange | positions so that it may have the opening part in the water absorbing material 16 arrange | positioned below. In this way, a part of the water supplied from the water supply port 6 of the water supply pipe 5 to the inside of the container is held by the water absorbing material 16, and the remaining part reacts with the hydrogen generating material 2 to generate heat of hydrogen generation. The reaction is started. The generated hydrogen is led out of the hydrogen production apparatus through the hydrogen lead-out port 7 through the hydrogen lead-out pipe 8, and is supplied to, for example, the negative electrode of the fuel cell. Although the water absorbing material 16 is not necessarily required, the water held by the water absorbing material 17 is also supplied to the hydrogen generating material 2 according to the consumption of water due to the exothermic reaction of hydrogen generation. It is effective in suppressing fluctuations.

  The water-absorbing material 17 is not particularly limited as long as it is made of a material that can absorb and hold water, and generally absorbent cotton or nonwoven fabric can be used.

  As shown in FIG. 3, the fuel cell system 200 of the present embodiment draws hydrogen from the hydrogen production apparatus 100 of the present embodiment and the hydrogen supply flow path 14 connected to the hydrogen outlet pipe 8 of the hydrogen production apparatus 100. It has a fuel cell 20 that flows in and uses this hydrogen as fuel to generate electricity. The fuel cell 20 is a well-known polymer electrolyte membrane fuel cell (PEMFC) that reacts with oxygen using hydrogen as a fuel, and is a solid polymer electrolyte as an electrolyte and air as a positive electrode active material. Hydrogen fuel is used for the oxygen and the negative electrode active material. Since the configuration of this fuel cell is general, illustration and detailed description thereof are omitted.

  As described above, as the second embodiment of the present invention, the fuel cell system including the hydrogen production apparatus of the present invention and the fuel cell using the hydrogen production apparatus and hydrogen produced by the hydrogen production apparatus as fuel has been described. The hydrogen production apparatus of the invention is not limited to one that produces hydrogen as a fuel for a fuel cell, but can be generally used as a hydrogen production apparatus for supplying hydrogen to a hydrogen storage container. .

  In the present embodiment, the reaction rate detection means for detecting the reaction rate of the hydrogen generating material 2 is described as the pressure sensor 11 disposed between the container 1 and the heat insulating material 9 that also serves as a container container. However, as explained in the first embodiment, as the reaction rate detection means in the present invention, a flow meter for detecting the total amount of generated hydrogen can be used. In this case, the amount of produced hydrogen can be detected by arranging the flow meter in the hydrogen outlet pipe 8 for sending out hydrogen from the container 1 or in the hydrogen supply path 14. Then, by inputting the total amount of the hydrogen generating material 2 accommodated in the container 1 to the control unit 12, the theoretical total amount of hydrogen generation is calculated, and this value and the actual amount obtained by the flow meter are generated. Based on the amount of hydrogen thus obtained, the current reaction rate of the hydrogen generating material 2 can be calculated. In this case, the container housing part 9 for housing the container 1 used in the hydrogen production apparatus 100 of the present embodiment can be omitted. In addition, when not using the container accommodating part 9, it is set as the structure which the heat insulating material 17 covers the outer surface of the container 1. FIG.

  When the hydrogen production apparatus of the present invention is configured as described above, the hydrogen production method of Embodiment 1 can be carried out as it is, and hydrogen can be produced simply and efficiently. In particular, by detecting the reaction state of the hydrogen generating material with water as a reaction rate, it is possible to stop hydrogen generation simply and efficiently, and to provide a hydrogen production apparatus suitable for use in a cordless device or the like. Can do.

(Embodiment 3)
Next, another embodiment of the fuel cell system of the present invention will be described. In addition, description may be abbreviate | omitted about the matter which is common in the matter demonstrated as Embodiment 1 and Embodiment 2. FIG.

  The fuel cell system shown in the third embodiment further includes a fuel cell system including a fuel cell 20 that generates power using hydrogen generated by the hydrogen generator 100 according to the second embodiment described with reference to FIG. A secondary battery for storing the generated electric power is provided. In addition, as this secondary battery, a well-known secondary battery such as a lithium ion battery can be used, and a well-known battery can be used as it is as a power charging mechanism. For this reason, a detailed description of the secondary battery and the fuel cell system in a state where the secondary battery is connected will not be given.

  The fuel cell system of Embodiment 3 uses the surplus hydrogen described in Embodiment 1 for power generation in the fuel cell, and describes the flow of processing for storing the power generated by this surplus hydrogen.

  FIG. 5 is a flowchart showing steps when controlling charging of the secondary battery in the hydrogen production method of the present embodiment. As shown in FIG. 5, the flow of processing in the present embodiment is a portion related to the production and surplus hydrogen surplus shown as step S <b> 105 in FIG. 1.

  After the production of surplus hydrogen, which is Step S105 in FIG. 1, is started, the reaction rate X of the hydrogen generating material is obtained in Step S306.

  Next, in step S307, it is determined whether or not the acquired reaction rate X is equal to or greater than the battery charge threshold value x3. This battery charging threshold value x3 is grasped as a level at which power generation by the fuel cell can be performed at a minimum and the secondary battery can be charged as the reaction rate of the hydrogen generating material. For this reason, the battery charging threshold value x3 is a numerical value that should be appropriately determined according to the type and amount of the hydrogen generating material, the power generation efficiency of the fuel cell, and the like.

  In step S307, when the reaction rate X of the hydrogen generating material is equal to or greater than the battery charging threshold x3 (in the case of Yes), most of the hydrogen generating material has already reacted with water and is necessary for power generation in the fuel cell. It is determined that it is difficult to generate hydrogen, and the process returns to step S106 to stop the supply of water. This is to avoid troubles such as excessive supply of water by continuing to supply water unnecessarily to hydrogen generating materials that cannot be expected to react.

  On the other hand, when the reaction rate X of the hydrogen generating material is not equal to or higher than the battery charging threshold x3 in step S307 (in the case of No), the process proceeds to the next step S308.

  In step S308, the charging current I charging the secondary battery is detected. The charging current I can be detected easily using an ordinary electric circuit means.

  In step S309, the detected current value I of the secondary current is compared with a predetermined current threshold value i1, and it is determined whether I is equal to or greater than i1. Here, the current threshold value i1 indicates the level of the current value at which the secondary battery can be actually charged with the power generated by the fuel cell. Therefore, the current threshold value i1 is a numerical value that should be appropriately set based on the characteristics of the secondary battery incorporated in the fuel cell.

  In step S309, when the charging current I is equal to or greater than the current threshold value i1 (in the case of Yes), the secondary battery is being charged with the surplus hydrogen being generated, so the secondary battery is continuously charged. While performing, it returns to step S306 and detects the reaction rate X of the hydrogen generating material.

  On the other hand, if the charging current I is not greater than or equal to the current threshold value i1 in step S309 (No), it is determined that the surplus hydrogen that is generated is in a state where the fuel cell cannot sufficiently generate power. For this reason, it transfers to step S106, supply of water is stopped, and manufacture of surplus hydrogen is complete | finished. Even if the reaction rate X is lower than the battery charging threshold x3, the secondary battery is not sufficiently charged with the power generated from the fuel cell in practice. This is because it is more important to prevent the occurrence of troubles such as overflow of excess water even if water is supplied to cause generation, which is ineffective.

  As described above, according to the method of the present embodiment, when surplus hydrogen is used to generate power in the fuel cell and the power is stored in the secondary battery, the reaction rate of the hydrogen generating material and the charging current to the secondary battery By using this as an index, it is possible to detect whether or not a sufficient amount of hydrogen is generated to charge the secondary battery, and the production of surplus hydrogen can be stopped accurately. For this reason, in the hydrogen production method of the present invention shown as Embodiment 1, it is possible to more effectively secure and utilize surplus hydrogen. As a result, the hydrogen generating material can be used as much as possible without being wasted, and the hydrogen generating apparatus can be stopped at an appropriate timing.

  In the third embodiment, the charge current I is detected and used as an index for detecting the remaining charge capacity of the secondary battery. However, the hydrogen generation method of the present invention is not limited to this. . In addition to the charging current, a charging voltage, an output voltage of the fuel cell, an output current, or the like can be used as an index for determining whether or not the secondary battery is effectively charged.

  As described above, the hydrogen production method and the hydrogen production apparatus of the present invention can be widely used industrially as those capable of producing hydrogen simply, efficiently and stably. In addition, this hydrogen production apparatus and a fuel cell system including a fuel cell using hydrogen as a fuel can be widely used including a power source for small portable devices.

It is a flowchart which judges the reaction rate of the hydrogen generating material in the case of stopping hydrogen production in the hydrogen production method as Embodiment 1 of the present invention. It is a flowchart which judges the reaction rate of the hydrogen generating material in the case of restarting, after stopping hydrogen production in the hydrogen production method as Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the hydrogen production apparatus as Embodiment 2 of this invention, and a fuel cell system. It is a schematic block diagram which shows the container 1 at the time of making the hydrogen production apparatus as Embodiment 2 of this invention into a fuel cartridge. It is a flowchart which judges the reaction rate of a hydrogen generating material in the case of storing the electric power generated with the fuel cell using the surplus hydrogen in a secondary battery in the hydrogen production method as Embodiment 3 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container 1a Cover 1b Container main-body part 2 Hydrogen generating material 3 Water storage container 4 Water 5 Water supply pipe 6 Water supply port 7 Hydrogen outlet 8 Hydrogen outlet pipe 9 Container accommodating part 10 Pump (water supply means)
11 Pressure sensor (reaction rate detection means)
DESCRIPTION OF SYMBOLS 12 Control part 13 Attachment / detachment mechanism 14 Hydrogen supply flow path 15 Stopper 16 Water absorption material 17 Thermal insulation material 100 Hydrogen production apparatus 200 Fuel cell system

Claims (15)

In a hydrogen production method for producing hydrogen by supplying water to a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water,
Detecting the reaction rate, which is the proportion of the amount already used for hydrogen generation in the hydrogen generating material when stopping the production of hydrogen;
When the reaction rate of the hydrogen generating material is larger than a stop threshold, hydrogen production is continued to generate surplus hydrogen, and the surplus hydrogen is separately utilized.   The hydrogen production method according to claim 1, wherein the surplus hydrogen is stored and used.   The hydrogen production method according to claim 1, wherein the surplus hydrogen is used to generate power in a fuel cell, and the generated power is used by charging a secondary battery.   After the hydrogen production is stopped, when the hydrogen production is started again, if the reaction rate of the hydrogen generating material is larger than the restart threshold, the hydrogen production is not started and the hydrogen generating material is replaced. The hydrogen production method according to any one of claims 1 to 3, wherein a warning display is provided.   The method for producing hydrogen according to claim 1, wherein the reaction rate of the hydrogen generating material is detected from the total amount of produced hydrogen.   The hydrogen production according to any one of claims 1 to 4, wherein a reaction rate of the hydrogen generating material is detected by a pressure between a container in which the hydrogen generating material is stored and a container storage unit in which the container is stored. Method.   7. The hydrogen generating material contained in the hydrogen generating material is at least one metal material selected from the group consisting of aluminum, silicon, zinc, magnesium and alloys mainly composed of these elements. The hydrogen production method according to any one of the above.   The method for producing hydrogen according to any one of claims 1 to 7, wherein the hydrogen generating material further includes a heat generating material that generates heat by reacting with water in addition to the hydrogen generating material.   The method for producing hydrogen according to claim 8, wherein the heat generating material is an alkaline earth metal oxide.   The hydrogen production method according to claim 8, wherein a content rate of the hydrogen generating substance in the hydrogen generating material is 85 wt% or more and 99 wt% or less. A container capable of containing a hydrogen generating material containing a hydrogen generating material that generates hydrogen by an exothermic reaction with water;
Water supply means capable of supplying water to the hydrogen generating material in the container at a predetermined supply time and a predetermined supply rate;
A reaction rate detecting means for detecting a reaction rate which is a ratio of an amount already used for hydrogen generation in the hydrogen generating material;
11. A hydrogen production apparatus used in the hydrogen production method according to claim 1.   The hydrogen production apparatus according to claim 11, wherein the container is detachable.   The hydrogen production apparatus according to claim 11 or 12, further comprising a stopper for restricting attachment / detachment of the container. A hydrogen production apparatus according to any one of claims 11 to 13,
A fuel cell system comprising: a fuel cell that generates electricity using hydrogen produced by the hydrogen production apparatus.   The fuel cell system according to claim 14, further comprising a secondary battery in which electric power generated by the fuel cell using the surplus hydrogen is charged.

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